Internal combustion engines require two independent circuits for the flow of inlet and exhaust gases. The combustion chambers are circular in shape dictated by the design of the cylinder, and it is not known whether the valves which admit the gases give a better result if they are not similarly circular in shape, the fitting of which is in the form of a truncated cone, usually called the seating zone. However, this shape requirement gives rise to drawbacks relating to the measurements of the heads of the valves, since the circular shape leaves large useless spaces when there are two or more figures coming together in the same space. These problems bring about an insufficient proportioning of the heads of the valves, which prevents the cylinder from receiving and expelling an amount of gas flow appropriate to the size of the circumference of the piston.
The very nature of internal combustion in engines prevents, on the other hand, priority being given to the development of the dimensions of one valve over another, since any possible enlargement of the inlet valve would necessitate proportionally enlarging the exhaust valve, and that, due to the limited measurements of the combustion chamber, is obviously impossible.
Currently, some engine manufacturers have developed a system of multiple valves which, although they are smaller than the usual ones, achieve a higher efficiency, since as they are manufactured in pairs, that is two inlet valves and two exhaust valves, they form a smaller surface of dead space between their circular heads.
Another method of alleviating this problem is the application of turbine powered supercharging. This is a solution which presents considerable well documented problems, fundamentally due to the large dead zones in which the turbine does not provide an appreciable minimum of excess pressure.
The double-flow valve which is the subject of this invention endeavours to resolve the problems described above, to which end it multiplies the space available for the flow of gases, and it does this in a completely new and revolutionary way, channelling the inlet and exhaust gases independently along its external and internal sides. To do this, the said valve presents two seating surfaces, one on its external side which seats on the cylinder head, and the other on its internal side which serves as seat for a conventionally designed valve, but which is naturally larger than the usual ones. This conventional valve opens and closes the passage of gases on the inside. The double-flow valve, on which this invention is based, has two rods which receive the thrust of two cams, which operate simultaneously.